The present technology relates generally to an AD converter, a signal processing method, a solid-state imaging device, and an electronic apparatus, and specifically, to an AD converter, a signal processing method, a solid-state imaging device, and an electronic apparatus that can decrease the generation of the streaking with simple circuit configurations.
The column AD-type CMOS image sensor performs a Correlated Double Sampling (CDS) process for deleting fixed pattern noises specific to pixels. In the CDS process, an analog pixel signal output from each pixel is compared with a ramp signal that decreases with a constant slope over time by a comparator. Subsequently, for example, down-count performed while a Hi difference signal is only supplied as a comparison result in a Preset Phase (P-phase) period, and up-count performed while a Hi difference signal is only supplied as a comparison result in a Data Phase (D-phase) period.
In the CDS process according to the related art, when an image in which a white region partially exists on a black background is captured, streaking is generated. The streaking refers to a phenomenon in which pixels to be a black background in the horizontal direction of a white region become gray on an image in which the white region partially exists on the black background. A main cause of the generation of the streaking is distortion of a ramp signal by a crosstalk from an output of a comparator.
The applicant of the present application has previously suggested a method of decreasing the generation of the streaking in Japanese Unexamined Patent Application Publication No. 2010-161484.